I would make a reservation, but maybe not through Disney. This last weekend, we ate there on Friday night. I called them direct at 4:30 to make a reservation. They said that pretty much everything was open for that night for a party of 7. I chose 8. We took the bus from our hotel and another group that was on the bus with us (a party of 6) who walked up right behind us at Rainforest Cafe was not seated for at least an hour after we were (they were seated at a table next to us).